Devices for shifting type carriers in electric typewriters and the like

ABSTRACT

A type carrier shifting band is trained about a pair of guide rollers journalled on the carriage and between which the band is controllably looped about a plurality of band-length adjusting rollers operatively related to levers which are relatively rockable by a motor cam. In addition, means are provided for selectively controlling the band-length adjusting rollers to attain desired positions of the type carrier within its operating range.

Umted States Patent 11 1 [111 3,773,159 Koller Nov. 20, 1973 [5 DEVICES FOR SHIFTING TYPE CARRIERS 2,905,301 9 1959 IN ELECTRIC TYPEWRITERS AND THE 3,420,350 H1969 LIKE 2,757,775 8/1956 2,769,029 10/1956 Inventor: Rudolf Koller, Aachen, Germany Siemens Aktiengesellschaft, Berlin and Munich, Germany Filed: Mar. 30, 1971 Appl. No.: 129,388

Assignee:

Foreign Application Priority Data Apr. 21, 1970 Germany P 20 19 222.7

References Cited UNITED STATES PATENTS 4/1961 l-Iickerson 197/16 Primary Examiner-Emest T. Wright, Jr. Att0rneyl-Iill, Sherman, Meroni, Gross & Simpson [57] ABSTRACT A type carrier shifting band is trained about a pair of guide rollers joumalled on the carriage and between which the band is controllably looped about a plurality of band-length adjusting rollers operatively related to levers which are relatively rockable by a motor cam. In addition, means are provided for selectively controlling the band-length adjusting rollers to attain desired positions of the type carrier within its operating range.

19 Claims, 5 Drawing Figures DEVICES FOR SHIFTING TYPE CARRIERS IN ELECTRIC TYPEWRITERS AND THE LIKE This invention relates to electrically driven typewriters and similar machines, and is more particularly concerned with devices for shifting type carriers to effect selective orientation in printing position of a plurality of keys, type bars or type faces in the operation of the machines.

Arrangements have been proposed heretofore to effect type carrier shifting in which a plurality of imprinting character faces are located one above the other and must be selectively oriented with respect to the printing position. In one such arrangement, a band is quided on the order of 180 about adjustable guide rollers whereby an individual adjustment of one g uide roller or a desired combination of guide rollers to a certain range effects a change at the carriage end of a shifting band where one end of the band is fixed. It is common to actuate the guide rollers by means of electromagnets influenced by the control criteria as, for instance in German published application 1,027,713. However, there is a demand for control criteria with high energy values, in particular for higher operational speeds where carrier shifting bands are employed since these control criteria are required to perform the entire work for the shifting of the member-to-be-adjusted, namely, the type carrier within a very short time interval. The adjusting criteria, however, usually do not possess the requisite higher energies, so that an electrical or mechanical amplification, for example, is necessary. For instance a cam-type drive has been suggested by way of mechanical amlification. Adjustment of the individual guide rollers of the band drive is executed in such case by the cam which is driven by an auxiliary drive such as an electric motor depending on the position of a coupling element, which, in the at-rest phase, can be adjusted by the control criteria with little waste of energy, exemplified in German published application 1,2 17,1 18.

According to the present invention, the disadvantages, defects, inefficiencies, shortcomings and problems in prior structures, such as referred to hereinabove, are overcome and important advantages and improvements are attained by the present invention affording an efficiently functioning device operating with minimum care and wear, in a simple structure which is easy to construct.

An important object of the invention is to provide a new and improved device for shifting type carriers in electric typewriters and the like Another object of the invention is to provide new and improved means for easily, quickly, efficiently and at high speed modifying the length of travel of a type carrier shifting band.

A further object of the invention is to provide a new and improved control means for type carrier shifting devices embodying shifting band pulleys or rollers.

Still another object of the invention is to provide new and improved quick-acting control mechanism for type carrier shifting devices.

One of the features of the invention is to provide a device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion, movable means supporting certain of the rollers, means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions, and means for selectively holding said certain rollers against cyclic movement with the supporting means therefor whereby to increase the number of effective carrier-shifting band lengths and thus the number of printing positions of the carrier.

Another feature of the invention is to provide a simple and efficient lost motion connection between one or more of the band-length-shifting control rollers and the movable supporting means such as a lever in the type carrier shifting device to enable selectively operable stop means to hold the roller against following the supporting means during a portion of a band-length varying cycle.

Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawing, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:

FIG. 1 is a schematic illustration of a type carrier shifting device adapted for threestage shifting;

FIG. 2 is a schematic illustration of a modification adapted for four-stage shifting with the aid of an additional motion-controlling means; and

FIG. 3 is a schematic illustration of a modified mounting of one of the rollers;

FIG. 4 is another modified mounting of one of the rollers; and

FIG. 5 is still another modified mounting of one of the rollers.

According to the present invention as exemplified in FIG. 1, a device for shifting a type carrier in fulfillment of the aims and objects hereinbefore expressed, is characterized in that the guide rollers over which the carrier shifting band is serpentinely looped are arranged to be supported in alternate relationship on respective levers arranged to be actuated by a common cam in association with the spring tension applied to the band through the carrier. In this arrangement the distances of the guide rollers from the pivot axes of the rollercontrolling levers are proportional to the desired range of movement of the respective rollers. Individual control elements are associated with the respective rollers so that although the rollers are normally carried by the control levers operatively moved by the cam, stops on the control elements are adapted to be selectively effective to hold the rollers in the farthest limit positions thereof to which they are respectively moved by the associated cam-actuated levers.

More specifically, in the form of FIG. 1, a three-stage carriage shifting band is provided in which compound movements up to 2 are attainable, i.e. eight adjusted positions can be obtained. As applied to a Telex machine for lifting and lowering a roller-shaped type carrier, seven print face or key rows can thus be provided one above the other any one of which is respectively shiftable into the printing position, in addition to an initial position wherein the print-receiving area is clear of the type carrier for unobstructed inspection. To this end, a shifting band 1 is fixed at one end to carriage C, is successively looped, serpentine fashion, under and around a pulley or roller 2 then over and around a pulley or roller 3, thence under and around a pulley or rol let 4, followed by over and around a roller and finally under and around a roller 6, with the opposite end of the shifting band 1 anchored to type carrier TC which is normally biasd into biased initial or clearance position as by means of a spring S. In this instance, the endmost rollers 2 and 6 serve as guide rollers and are desirably journalled on fixed axles 2a and 6a, respectively, on the carriage C. Thereby the band 1 is maintained under constant tension against all of the rollers 2,3,4,5 and 6 by the spring S.

By reason of the normally tensioned condition of the shifting band 1, it acts on the rollers 3 and 5 to maintain respective axles 3a and 5a thereon in appropriate upwardly opening lost motion journal slots 3b and 5b, respectively, in the upper lever 7, and the axle 4a of the roller 4 in a downwardly opening lost motion journal slot 4b in the lower lever 8. Through this arrangement, the levers 7 and 8 are by the tension of the band 1 applied to the rollers 3, 4 and 5, normally biased toward a cam 9 which is corotatably mounted on a shaft 90 having its axis in a fixed relation between the ends of the levers 7 and 8 which are nearest the guide roller 6, and driven in suitable manner as by means of an electrical motor (not shown). Desirably, the cam 9 is of the double lobe type with the lobes diametrically opposite such that as the cam 9 turns with the shaft 9a respective followers 7a and 8a on the adjacent ends of the levers 7 and 8 riding the cam 9 are simultaneously driven apart when riding the lobes and then move toward one another on the cam 9 between the lobes, twice in each complete cycle of rotation of the cam 9, the lever 7 rocking about a fixed axle 13 at its opposite end and the lever 8 rocking about a fixed axle 14 at its opposite end.

As the cam 9 rotates and thus rocks the roller control levers '7 and 8 between the maximum separated and minimum separated conditions of the cam-operated lever ends, the rollers 3, 4 and 5 riding with the levers 7 and 8 will correspondingly shorten the extent of the band 1 between the roller 6 and the type carrier TC when the lever followers 7a and 8a are at the tips of the cam lobes, and under the bias of the spring S enable lengthening of the extent of the band 1 between the roller 6 and the type carrier TC to maximum extent when the lever followers 7a and 8a are on the smallest diameter of the cam 9. Thereby, in each half revolution of the earn 9 there is the capability of movement of the type carrier TC between the extreme ends of its range of movement, for example between its first and eighth po sitions.

In order to effect shifting of the type carrier TC into any one of the remaining six positions selectively, means are provided for holding any one or a combination of the intermediate, lever-journalled rollers 3, 4, and 5 against movement with its respective lever from the maximum separated condition of the levers 7 and 8, to thus control the amount of extension of the band 1 in the direction of the type carrier TC under the bias of the spring S as the cam 9 turns from its maximum diameter contact with the lever followers 7a and 8a to its minimum diameter contact with the followers 7a and 8a. To this end, means are provided comprising selectively operable stops 10, 11 and 12 which are operable with respect to the rollers 3, 5 and 4, respectively and carried by respective slides or longitudinally shiftable control bars 100, 11a and 120, respectively. These stops 10, 11 and 12 are selectively operable through their control bars 10a, 11a and 12a to engage with the respective axles 3a, 5a and 4a of the associated control rollers 3, S and 4 when they have reached the position of maximum separation of the carrying levers 7 and 8 to hold the associated roller 3, 5 or 4 against following its lever 7 or 8 in the direction of swinging together of the levers 7 and 8, thereby to that extent holding the band 1 against lengthening toward the type carrier TC. In the relationship shown in FIG. 1, the axles 3a, 4a and 5a of the lever-carried rollers 3, 4 and 5 relative to the pivotal axles l3 and 14 of the respective levers 7 and 8 and to each other is such that there is 1:214 ratio which is attained by having the lever 7 longer than the lever 8 to the extent that the lever axle 13 is located appropriately above and to the left of the axle 20 for the fixed axis roller 2 while the axle 14 of the lever 8 is located generally vertically aligned below the axle 2a of the roller 2, while the followers and 8a of the levers 7 and 8 are generally vertically aligned with the shaft of the cam 9. Further, the axle 3a of the roller 3 lies spaced from the lever axle 13 a distance which brings it into a vertical position to the right of the axle 2a of the roller 2 and spaced a substantially greater distance from the opposite end of the lever 7 where the axle 5a of the roller 5 is vertically aligned with the cam follower 7a of the lever 7. On the other hand, the axle 4a of the roller 4 is spaced a greater distance from the axle 14 of the lever 8 than it is spaced from the follower 8a of the lever 8. Nevertheless, in the preferred relationship, the respective axle 2a, 3a, 4a and 5a of the rollers 2, 3, 4, S and 6 are located in vertical planes along those 20, 3a, 4a and 5a axles which are substantially equally spaced. Through this arrangement, by the appropriate selective holding or release of the intermediate rollers 3, 4 and 5, by shifting of the respective stops 10, 12 and 11 into or out of holding position, effects positioning of the type carrier TC in the six possibilities between the maximum range one and eight positions, as well as these one and eight positions, smoothly, rapidly and with maximum efficiency in the operation of the associated machine.

Although the carrier shifting band 1 may be adjustably anchored to the carriage C to effect initial adjustments, wherefore it is desirable to have the guide roller 2 rotatably mounted, during normal operation of the device, this roller 2 may serve simply as a loop guide for the band 1 relative to the roller 3 and remains relatively stationary. Thereby only the type carrier TC will be shifted during actuation of the device in operation, the band 1 having no motion imparting or effecting action with respect to the carriage C.

In a modified arrangement of the device according to FIG. 2, for example, additional means are provided for increasing the shifting range, or the number of shifting intervals, or the spacing between intervals, or the like, of the type carrier TC relative to the carriage C. To this end, the device of FIG. 2 comprises substantially the same rollers 2,3, 4 and 5 as in the form of FIG. 1, with the flexible carrier shifting member or band 1 looped in serpentine fashion over the rollers 2', 3, 4 and 5 between the length of the band ll that extends from the carriage C and the length of the band 1' which extends to the type carrier TC. Although the spacing planes between the controlling and guide rollers 2, 3', 4 and 5 remain the same as in FIG. 1, it will be observed that the levers 7 and 8 are shorter in FIG. 2 so that the rocking radius of these levers 7' and 8' is correspondingly shorter in FIG. 2. Further, the stop means for holding the rollers 3 and 5 selectively against movement with the lever 7' in the rocking of the levers 7' and 8 toward one another in riding the short diameter portions of the cam 9, comprise respective rocker stop arms and 16. For similarly holding the roller 4, a rocker stop 17 is provided. In this instance, the stop arms 15 and 16 are carried on the axles 3a and 5a of the rollers 3 and 5, respective biasing means such as springs 18 and 19 normally holding the stop arms 15 and 16 clear of respectively fixed stop shoulders 20 and 21 respectively. Means such as a shifting link 15a are provided connected to the rocker stop arm 15 to move it selectively into engagement with the stop shoulder 20 for holding the roller 3. Similar means or a selectively operable thrust member 16a is provided to move the stop arm 16 selectively into engagement with the stop shoulder 21 to hold the roller 5. Holding of the roller 4 is effected, in this instance, by holding the lever 8 on which the roller 4 is rotatably mounted on a fixed axis 4a, this lever 8' being provided with an upstanding fin ger 23 on its free or distal end portion which is selectively engageable by the rocker stop 17, normally biased as by means of a spring 17a into stopping engagement with the finger 23, but shiftable in opposition to the spring bias by means such as a link 17b into clearance relation to the finger 23.

Another feature of the form of FIG. 2 resides in that a range of control over the length of the band 1 connected to the type carrier TC is additionally adjustably attained by means of a lever 24 having a fixed axis 24a to the left of the cam 9 and a follower 24b riding on the cam 9 alongside the follower 7a for the lever 7 and with the lever 24 extending to the right of the cam 9 and normally biased toward the cam 9 by a spring 25 so that a guide roller 26 taking the place of the roller 6 in FIG. 1 is normally caused to move shiftably with coincident rocking of the levers 7' and 24 by following the rotating cam 9. Selectively, the lever 24 may be held by a rockably mounted detent shoulder stop 27 against following the cam 9 from a high point to a low point. Normally the rocking detent shoulder stop 27 is biased by means such as a spring 27a into a position clear of the cooperative end of the lever 24, but is adapted to be selectively shifted in opposition to the bias of the spring 27a by means such as a plunger 27b.

Further control of the device of FIG. 2 is attained by means associated with the roller 2 for lengthening or shortening the band 1' with respect to the type carrier TC. For this purpose, the end of the tension band 1 connected to the carriage C may be provided with limited tensionable extension means such as a contractile spring SS so that by rotation of the roller 2 about its axis 2a the band 1' may be elongated by pulling against the spring SS, as by means of teeth 2b on the perimeter of the roller 2 meshing with complementary lugs or teeth 1a on the band 1'. Such rotation of the roller 2' within a limited range is adapted to be effected by means of a pawl and ratchet mechanism including a generally dog leg lever 28 rockable on the axis 14 and having a follower 28a riding the cam 9 adjacent to but independently of the follower 8a of the associated lever 8, whereby in the rotation of the cam 9 and thus rocking of the lever 28, a spring biased pawl 29 will engage with ratchet teeth 30. For selectively disabling the pawl 29, means such as a depressor 31 operating in opposition to bias of the pawl spring 29a may be provided.

Instead of the pawl and ratchet mechanism 29, 30 and meshing arrangement of the roller 2 with the band I, a similar roller 201 (FIG. 3), located in about the same relation to the lever pivots l3 and 14 as the roller 2', may be mounted intermediately on a rocking lever 32 similarly as the lever 24 mounts the roller 26. The lever 32 is arranged to be operated by the cam 9 against the bias of a lever biasing spring 320 through a follower 32b at a distal end of the lever 32 which is pivotally supported to rock about a pivot 32c at its proximal end. One of the existing rocking levers 7 or 8 could be modified (7", 8") to mount the roller 2' as shown at 202 (FIG. 4) and 203 (FIG. 5), with suitable stop means, exemplified by 211 and 215 but not limited thereto, similar to the stop means 11 and 16 of FIGS. 1 and 2, respectively, provided to control the roller 202 or 203.

In the operation of the device of FIG. 2, in addition to the length control enabled through the roller 2', the roller 26 affords a considerable additional range of control. The shifting distance enabled through the shiftably mounted roller 26 is twice that of the nearest guide roller 5, four times that of the next guide roller 4 in the series, and eight times that of the guide roller 3. This enables the type carrier TC to be normally in a position between opposite ends of a range of shifting adjustment and relative to which normal position it can be selectively shifted by desirable incremental stages in either opposite direction.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising:

a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion;

movable means supporting certain of the rollers, in-

cluding an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong;

means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions;

said two rollers having respective lost motion connection with said member; and

means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting meeans therefor;

whereby to provide for a number of effective carriershifting band lengths and thus a number of printing positions of the carrier.

2. A device according to claim 1, comprising a staggered series of five control rollers, in which in addition to said two rollers two other rollers are mounted on fixed rotary axes, and a second elongated cyclically movable member supporting the remaining of the five rollers.

3. A device according to claim 1, wherein said control rollers comprise a series of five, one of the rollers at one end of the series being mounted on a fixed axis, and said certain rollers comprising the remaining four rollers including said two rollers, said supporting means comprising a plurality of levers one of which is said elongated member on which said two of the rollers are supported, a second lever supporting one of the remaining rollers and a third lever supporting the other of the remaining rollers, and said means operative to move the supporting means comprising a common rotary cam toward which the levers are biased by tension of the band working against the rollers.

4. A device according to claim 3, wherein two of the three levers have followers adjacent to one end portion thereof engaging the cam, and the third lever has an intermediate portion thereof in engagement with the earn, a pivot at one end portion of the third lever and the roller supported by the third lever being located on an opposite end portion of the third lever.

5. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising:

a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion;

movable means supporting certain of the rollers, in cluding an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong;

means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions;

means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting means therefor;

said member comprising a rocking lever provided with a transverse journal slot in which an axle on one of said certain rollers is journalled;

said means for selectively holding comprising a stop operative to hold said certain one of the rollers through said axle against continuing cyclic rocking movement with the lever;

whereby to provide for a number of effective carriershifting band lengths and thus a number of printing positions of the carrier.

6. A device according to claim 5, said means for selectively holding including a shiftable control bar mounting said stop.

7. A device according to claim 5, in which said stop comprises a rockably mounted member on the roller axle, means normally biasing the rockably mounted member into inactive position, a fixed stop shoulder engageable by the stop, and means for moving said stop selectively into engagement with said shoulder,

8. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising:

a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion;

movable means supporting certain of the rollers, in-

cluding an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong;

means operative to move the supporting means cycli cally to vary the effective band length for shifting of the carrier between at least two printing positions;

means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting means therefor;

said member comprising a first lever pivotally mounted at one end and having a cam follower at its opposite end;

said means operative to move the supporting means cylically comprising a lobed cam operatively engaged by said follower whereby said first lever is rocked cyclically;

a transversely opening lost motion journal slot intermediate the ends of said first lever;

a second transversely opening lost motion journal slot in said first lever generally aligned with said follower;

said two rollers having axles journalled in said journal slots; and

said means for selectively holding said two rollers including stop members operable into and out of holding relation to the roller axles;

whereby to provide for a number of effective carriershifting band lengths and thus a number of printing positions of the carrier.

9. A device according to claim 8, including a second lever spaced from said first lever to lie on the opposite side of the cam therefrom and having a follower at one end engaging the cam and said second lever being pivotally mounted at an opposite end thereof, said second lever having a transversely opening lost motion journal slot, another of said certain rollers having an axle engaged in the slot of the second lever, and said means for selectively holding including another stop member operative for selective holding of the second lever roller through said axle of the second lever roller.

10. A device according to claim 9, in which said second lever roller is located in staggered relation in the serpentine band path between the two rollers of said first lever, and the distance of the axles of the three rollers relative to the pivotal axes of the respective first and second levers is in a 1:2:4 ratio considered in the staggered relation from the roller which is nearest the axes of the first and second levers to the roller which has the axle thereof journalled in said second transversely opening lost motion journal slot.

11. A device according to claim 8, including a second lever pivotally mounted at one end and having a follower adjacent to an opposite end engaging said cam and supporting another of said certain rollers, and said means for selectively holding comprising releasable detent means operative to engage the second lever for holding the second lever and the roller supported thereby against cyclic movement.

12. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising:

a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion;

movable means supporting certain of the rollers, in-

cluding an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong;

means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions;

means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting means therefor;

said supporting means comprising three rockably mounted levers one of which is said elongated member; and

said means operative to move the supporting means comprising a cam common to all three levers;

whereby to provide for a number of effective carriershifting band lengths and thus a number of printing positions of the carrier.

13. A device according to claim 12, wherein two of said levers have respective ones of the rollers fixedly journalled thereon, and said means for selectively holding comprising shiftable stops and means for shifting the stops.

14. A device according to claim 13, including a respective releasable stop for selectively holding each of said two levers against movement, means normally biasing one of said stops out of holding relation to the lever held thereby, and means normally biasing another of said stops into holding relation to the lever held thereby.

15. In a device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, with a plurality of shift control rollers relatively oriented to have the band looped thereover:

a roller supporting member;

means movably supporting at least one of said rollers on said member in a lost motion connection with the member;

means operative to move said member and thereby said one roller cyclically to vary the effective band length for shifting of the carrier relative to the carriage;

said supporting means and said one roller being normally held for movement with the member by the tension of the band on said one roller; and

means for selectively holding said one roller supporting means and thereby said one roller against cyclic movement with said member, as enabled by said lost motion connection.

16. A device according to claim 15, wherein said member is a lever and the lost motion connection comprises a bearing slot, and said one roller has as said supporting means an axle journalled in said slot.

17. A device according to claim 16, in which said means for selectively holding comprises a stop member movable between inactive position and a position to hold said axle against movement with the member.

18. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising:

a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion;

movable means supporting certain of the rollers;

means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions;

means for selectively holding said certain rollers against cyclic movement with the supporting means therefor whereby to provide for a number of effective carrier-shifting band lengths and thus a number of printing positions of the carrier;

yieldable means connected to said band enabling varying the actual carrier-shifting band length in addition to said effective carrier-shifting band length;

means for effecting selective rotation of one of said control rollers; and

means providing a driving connection between said one roller and said band to effect variation in carrier-shifting band length in the rotation of said one roller.

19. A device including a shifting band connected at one end to a carriage and at its opposite end to a type carrier which is shiftable relative .to the carriage and is normally yieldably biased in one direction, comprising:

a pair of elongated levers having one of their ends pivotally mounted in adjacent spaced relation and their opposite ends in relatively free adjacent spaced relation and provided with cam follower means;

a lobed cam rotatably mounted between and engaged by said follower means and operative in rotation of the cam to effect relative pivotal swinging of said levers;

a plurality of rollers supported on said levers and located in relative staggered relation to each other;

a looping member located generally between and spaced from said pivoted ends of the levers;

a looping roller located adjacent and spaced from said free ends of the levers;

said band being looped over said looping member,

said plurality of rollers and said looping roller serpentine fashion;

certain of said plurality of rollers having lost motion connection with one of said levers enabling movement of the certain rollers with the levers and also enabling movement of the levers while said certain rollers are held against movement with the levers;

said band normally by its tension maintaining said certain rollers for movement with said one of said levers; and

means for selectively holding said certain rollers against movement with said one of said levers whereby to vary the effective carrier-shifting band lengths while the levers continue in movement with thecam. 

1. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising: a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion; movable means supporting certain of the rollers, including an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong; means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions; said two rollers having respective lost motion connection with said member; and means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting meeans therefor; whereby to provide for a number of effective carrier-shifting band lengths and thus a number of printing positions of the carrier.
 2. A device according to claim 1, comprising a staggered series of five control rollers, in which in addition to said two rollers two other rollers are mounted on fixed rotary axes, and a second elongated cyclically movable member supporting the remaining of the five rollers.
 3. A device according to claim 1, wherein said control rollers comprise a series of five, one of the rollers at one end of the series being mounted on a fixed axis, and said certain rollers comprising the remaining four rollers including said two rollers, said supporting means comprising a plurality of levers one of which is said elongated member on which said two of the rollers are supported, a second lever supporting one of the remaining rollers and a third lever supporting the other of the remaining rollers, and said means operative to move the supporting means comprising a common rotary cam toward which the levers are biased by tension of the band working against the rollers.
 4. A device according to claim 3, wherein two of the three levers have followers adjacent to one end portion thereof engaging the cam, and the third lever has an intermediate portion thereof in engagement with the cam, a pivot at one end portion of the third lever and the roller supported by the third lever being located on an opposite end portion of the third lever.
 5. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising: a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion; movable means supporting certain of the rollers, including an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong; means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions; means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting means therefor; said member comprising a rocking lever provided with a transverse journal slot in which an axle on one of said certain rollers is journalled; said means for selectively holding comprising a stop operative to hold said certain one of the rollers through said axle against continuing cyclic rocking movement with the lever; whereby to provide for a number of effective carrier-shifting band lengths and thus a number of printing positions of the carrier.
 6. A device according to claim 5, said means for selectively holding including a shiftable control bar mounting said stop.
 7. A device according to claim 5, in which said stop comprises a rockably mounted member on the roller axle, means normally biasing the rockably mounted member into inactive position, a fixed stop shoulder engageable by the stop, and means for moving said stop selectively into engagement with said shoulder.
 8. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising: a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion; movable means supporting certain of the rollers, including an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong; means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions; means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting means therefor; said member comprising a first lever pivotally mounted at one end and having a cam follower at its opposite end; said means operative to move the supporting means cylically comprising a lobed cam operatively engaged by said follower whereby said first lever is rocked cyclically; a transversely opening lost motion journal slot intermediate the ends of said first lever; a second transversely opening lost motion journal slot in said first lever generally aligned with said follower; said two rollers having axles journalled in said journal slots; and said means for selectively holding said two rollers including stop members operable into and out of holding relation to the roller axles; whereby to provide for a number of effective carrier-shifting band lengths and thus a number of printing positions of the carrier.
 9. A device according to claim 8, including a second lever spaced from said first lever to lie on the opposite side of the cam therefrom and having a follower at one end engaging the cam and said second lever being pivotally mounted at an opposite end thereof, said second lever having a transversely opening lost motion journal slot, another of said certain rollers having an axle engaged in the slot of the second lever, and said means for selectively holding including another stop member operative for selective holding of the second lever roller through said axle of the second lever roller.
 10. A device according to claim 9, in which said second lever roller is located in staggered relation in the serpentine band path between the two rollers of said first lever, and the distance of the axles of the three rollers relative to the pivotal axes of the respective first and second levers is in a 1: 2:4 ratio considered in the staggered relation from the roller which is nearest the axes of the first and second levers to the roller which has the axle thereof journalled in said second transversely opening lost motion journal slot.
 11. A device according to claim 8, including a second lever pivotally mounted at one end and having a follower adjacent to an opposite end engaging said cam and supporting another of said certain rollers, and said means for selectively holding comprising releasable detent means operative to engage the second lever for holding the second lever and the roller supported thereby against cyclic movement.
 12. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising: a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion; movable means supporting certain of the rollers, including an elongated member on which two of the rollers are supported in longitudinally spaced relation therealong; means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions; means for selectively holding said two rollers against cyclic movement with said member as said member continues in the cyclic movement and a remaining of the certain rollers continues in the cyclic movement with the supporting means therefor; said supporting means comprising three rockably mounted levers one of which is said elongated member; and said means operative to move the supporting means comprising a cam common to all three levers; whereby to provide for a number of effective carrier-shifting band lengths and thus a number of printing positions of the carrier.
 13. A device according to claim 12, wherein two of said levers have respective ones of the rollers fixedly journalled thereon, and said means for selectively holding comprising shiftable stops and means for shifting the stops.
 14. A device according to claim 13, including a respective releasable stop for selectively holding each of said two levers against movement, means normally biasing one of said stops out of holding relation to the lever held thereby, and means normally biasing another of said stops into holding relation to the lever held thereby.
 15. In a device for shifting a type carrier which is normally yieldably biased in one direction relative to a printing area on a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, with a plurality of shift control rollers relatively oriented to have the band looped thereover: a roller supporting member; means movably supporting at least one of said rollers on said member in a lost motion connection with the member; means operative to move said member and thereby said one roller cyclically to vary the effective band length for shifting of the carrier relative to the carriage; said supporting means and said one roller being normally held for movement with the member by the tension of the band on said one roller; and means for selectively holding said one roller supporting Means and thereby said one roller against cyclic movement with said member, as enabled by said lost motion connection.
 16. A device according to claim 15, wherein said member is a lever and the lost motion connection comprises a bearing slot, and said one roller has as said supporting means an axle journalled in said slot.
 17. A device according to claim 16, in which said means for selectively holding comprises a stop member movable between inactive position and a position to hold said axle against movement with the member.
 18. A device for shifting a type carrier which is normally yieldably biased in one direction relative to a carriage in an electrically driven typewriter or the like, and including a tensioned shifting band connected at one end to the carriage and at the opposite end to the carrier, comprising: a plurality of shift control rollers relatively oriented in a staggered relation and having the band looped thereover serpentine fashion; movable means supporting certain of the rollers; means operative to move the supporting means cyclically to vary the effective band length for shifting of the carrier between at least two printing positions; means for selectively holding said certain rollers against cyclic movement with the supporting means therefor whereby to provide for a number of effective carrier-shifting band lengths and thus a number of printing positions of the carrier; yieldable means connected to said band enabling varying the actual carrier-shifting band length in addition to said effective carrier-shifting band length; means for effecting selective rotation of one of said control rollers; and means providing a driving connection between said one roller and said band to effect variation in carrier-shifting band length in the rotation of said one roller.
 19. A device including a shifting band connected at one end to a carriage and at its opposite end to a type carrier which is shiftable relative to the carriage and is normally yieldably biased in one direction, comprising: a pair of elongated levers having one of their ends pivotally mounted in adjacent spaced relation and their opposite ends in relatively free adjacent spaced relation and provided with cam follower means; a lobed cam rotatably mounted between and engaged by said follower means and operative in rotation of the cam to effect relative pivotal swinging of said levers; a plurality of rollers supported on said levers and located in relative staggered relation to each other; a looping member located generally between and spaced from said pivoted ends of the levers; a looping roller located adjacent and spaced from said free ends of the levers; said band being looped over said looping member, said plurality of rollers and said looping roller serpentine fashion; certain of said plurality of rollers having lost motion connection with one of said levers enabling movement of the certain rollers with the levers and also enabling movement of the levers while said certain rollers are held against movement with the levers; said band normally by its tension maintaining said certain rollers for movement with said one of said levers; and means for selectively holding said certain rollers against movement with said one of said levers whereby to vary the effective carrier-shifting band lengths while the levers continue in movement with the cam. 